JP3126316B2 - Apparatus and method for manufacturing multilayer printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for manufacturing a multilayer printed wiring board, and more particularly to an apparatus and a method for forming a via hole in a multilayer printed wiring board.

[0002]

2. Description of the Related Art A build-up multilayer wiring board has an interlayer resin insulating material and a conductive circuit layer alternately, a hole is provided in the interlayer resin insulating material layer, and a conductive film is formed on the wall surface of the hole to form an upper layer. And the lower layer are electrically connected. The holes (via holes) in the interlayer resin insulating layer are generally formed by exposing and developing the interlayer resin by making it photosensitive.

[0003] However, the diameter of via holes in multilayer printed wiring boards has become mainstream at 100 µm or less, and a technique for forming via holes of smaller diameter is required. From such demands, the use of a processing method using laser light for drilling holes in a build-up multilayer wiring board is being studied. Techniques that use lasers for drilling include, for example,
It has been proposed in JP-A-3-54884. In this technique, light from a laser light source is received and deflected by a processing head, and is irradiated on a predetermined resin insulating material to form a through hole.

[0004]

However, the number of via holes in a multilayer printed wiring board is several hundreds to several thousands in one layer, and the via holes must be electrically connected to the lower conductive circuit. Instead, high positional accuracy is required.
Therefore, in order to mass-produce a multilayer printed wiring board, it has been required to be able to position the laser with high accuracy.

An object of the present invention is to provide an apparatus and a method for manufacturing a multilayer printed wiring board which can form hundreds to thousands of holes by laser light irradiation while securing the positional accuracy of via holes. is there.

[0006]

According to a first aspect of the present invention, there is provided an apparatus for manufacturing a multilayer printed wiring board which is used for processing a multilayer printed wiring board having an interlayer resin insulating material. A scanning head for deflecting the direction of laser light in the XY directions, a camera for reading positioning marks on the multilayer printed wiring board, an XY table for mounting the multilayer printed wiring board, and a multi-layer printed wiring board. An input unit for inputting the processing data, a storage unit for storing the processing data or the calculation result, and a calculation unit. The processing data is input from the input unit, and the processing data is stored in the storage unit. The position of the positioning mark of the multilayer printed wiring board placed on the table is measured, and the processing unit corrects the input processing data based on the measured position, The drive data of the inspection head and the XY table are created and stored in the storage unit. The drive data is read from the storage unit by the control unit, and the XY table and the scanning head are controlled to emit the laser beam. A technical feature is that a multilayer printed wiring board is irradiated to remove the interlayer resin layer to form a hole.

According to a second aspect of the present invention, there is provided the apparatus for manufacturing a multilayer printed wiring board according to the first aspect, wherein the positioning mark is made of a conductive metal.

According to a third aspect of the present invention, there is provided an apparatus for manufacturing a multilayer printed wiring board, wherein the positioning mark is formed simultaneously with a conductor circuit.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, comprising: forming a positioning mark and an interlayer insulating layer on the multilayer printed wiring board; A scanning head for deflecting in the Y direction, a camera for reading positioning marks of the multilayer printed wiring board, an XY table for mounting the multilayer printed wiring board, and an input for inputting processing data of the multilayer printed wiring board Unit, a storage unit for storing processing data or a calculation result, and a multi-layer printed wiring board manufacturing apparatus comprising a calculation unit. Input to the device, measure the position of the positioning mark on the multilayer printed wiring board with the camera, and in the arithmetic unit, the measured position The processing data input is corrected based on the position of the mark, drive data for the scanning head and the XY table is created and stored in the storage unit, and the drive data is read out from the storage unit by the control unit. , XY
A technical feature is to control the table and the scanning head to irradiate the multilayer printed wiring board with laser light to remove the interlayer resin layer and form a hole.

In the present invention, a positioning mark is formed at a predetermined position on the multilayer printed wiring board in advance, so that the position of the positioning mark is measured with a camera, the position of the substrate is actually measured, and the input position is further determined. To correct the displacement of the substrate position from the processing data and the actual measurement value of the position of the substrate, create driving data for the scanning head and the XY table, and drive the scanning head and the XY table according to the driving data. It is possible to realize hundreds to thousands of via holes while maintaining high positional accuracy.

In the present invention, the positioning mark of the multilayer printed wiring board is desirably made of conductive metal. When the mark is read by the reflected light of the positioning mark, the metal has a high reflectance and is easily read by a camera. Further, when the positioning mark is read by the transmitted light, since the metal does not transmit the light, the positioning mark can be recognized by the silhouette and it is easy to read by the camera.

It is preferable that the positioning mark is formed at the same time as the formation of the conductor circuit. This is because there is no need to separately provide a positioning mark forming step. Specifically, a positioning mark can be formed when the copper-clad laminate is etched to form a conductor pattern. Further, a plating resist is provided on a portion where the conductor circuit and the positioning mark are not formed, and plating is performed to simultaneously form the conductor circuit and the positioning mark. As described above, when the conductor circuit and the positioning mark are formed at the same time, the positioning mark is covered with the interlayer resin insulating material, and therefore, it is desirable to use a translucent interlayer resin insulating material.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an apparatus for manufacturing a multilayer printed wiring board according to a first embodiment of the present invention. In this embodiment, a CO ₂ laser oscillator 60 is used as a laser source.
Is used. The light emitted from the laser oscillator 60 is sent to a galvano head 70 via a transfer mask 62 for sharpening the focus on the substrate.

The galvano head (scanning head) 70 includes a galvanometer mirror 74X for scanning the laser beam in the X direction and a galvanometer mirror 74Y for scanning the laser beam in the Y direction. 74X and 74Y are driven by control motors 72X and 72Y. The motors 72X and 72Y are configured to adjust the angles of the mirrors 74X and 74Y in accordance with a control command from a computer described later, and to transmit a detection signal from a built-in encoder to the computer.

The scanning area of the galvanometer mirror is 30 ×
30 mm. The positioning speed of the galvanomirror is 400 points / second in the scan area. The laser beam is scanned in the X and Y directions via the two galvanometer mirrors 74X and 74Y, and the f-θ lens 76 is scanned.
To form a hole (opening) for a via hole in contact with an adhesive layer described later of the substrate 10.

The substrate 10 has an XY moving in the XY directions.
It is placed on a table 80. As described above, the scan area of the galvanometer mirror of each galvano head 70 is 30 mm × 30 mm, and the substrate 1 of 500 mm × 500 mm is used.
Since 0 is used, the number of step areas in the XY table 80 is 289 (17 × 17). That is, the processing of the substrate 10 is completed by performing the movement of 30 mm in the X direction 17 times and the movement in the Y direction 17 times.

The manufacturing apparatus is provided with a CCD camera 82, which measures the positions of target marks (positioning marks) 11 provided at the four corners of the substrate 10, corrects errors, and starts processing. It is configured to be.

Next, a control mechanism of the manufacturing apparatus will be described with reference to FIG. The control device includes a computer 50. The computer 50 stores hole coordinate data (processing data) of the multilayer printed wiring board input from the input unit 54 and the position of the target mark 11 measured by the CCD camera 82. The data is input, processing data is created, and stored in the storage unit 52. Then, based on the processing data, the XY table 80, the laser 60, and the galvano head 70 are driven to perform actual drilling.

Here, the processing of creating processing data by the computer 50 will be described in more detail with reference to FIG. The computer 50 firstly operates the CCD camera 8
The XY table 80 is driven to move the target mark 11 to the position 2 (first processing). Then, by capturing the positions of the four target marks 11 with the CCD camera 82, errors such as a displacement amount in the X direction, a displacement amount in the Y direction, a contraction amount of the substrate, and a rotation amount are measured (second processing). Then, error data for correcting the measured error is created (third process).

Subsequently, the computer 50 corrects the hole coordinate data consisting of the coordinates of each machining hole with the error data created in the third processing, and creates actual machining data consisting of the coordinates of the hole to be actually drilled ( Fourth processing). And
Based on the actual machining data, galvano head data for driving the galvano head 70 is created (fifth step).
Processing), table data for driving the XY table 80 is created (sixth processing), and laser data for oscillating the laser 60 is created (seventh processing). The created data is temporarily stored in the storage unit 52 as described above, and based on the data, the XY table 80, the laser 60, and the galvano head 70 are driven to perform actual drilling.

Next, the manufacture of a multilayer printed wiring board using the apparatus for manufacturing a multilayer printed wiring board according to the first embodiment of the present invention will be described with reference to FIGS.
First, an 18 μm copper foil 12 is formed on both sides of a substrate 10 made of glass epoxy or BT (bismaleimide triazine) having a size of 500 × 500 mm and a thickness of 1 mm shown in step (A) in FIG.
Is used as a starting material, and the copper foil is etched in a pattern according to an ordinary method as shown in a step (B) to form inner layer copper patterns 14a, 14b, Then, the target mark 11 is formed.

Here, an interlayer resin insulating material is prepared. DM
Cresol novolak type epoxy resin dissolved in DG (dimethyl glycol dimethyl ether) (Nippon Kayaku:
Molecular weight 2500) of 70 parts by weight, polyethersulfone (PES) 30 parts by weight, imidazole curing agent (Shikoku Chemicals: 2E4MZ-CN) 4 parts by weight, and the average particle size of epoxy resin particles 5 0.5 μm
Was mixed with 35 parts by weight and 5 parts by weight of an average particle size of 0.5 μm, and further mixed while adding NMP, adjusted to a viscosity of 2000 cps with a homodisper stirrer, and kneaded with three rolls. An adhesive solvent (interlayer resin insulating material) is obtained.

After the substrate 10 shown in the step (B) is washed with water and dried, the substrate 10 is acid-degreased and soft-etched, and treated with a catalyst solution comprising palladium chloride and an organic acid to provide a Pd catalyst. Then, activation is performed, plating is performed in an electroless plating bath, and Ni—Ni is applied to the surfaces of the copper conductors 14a and 14b, the target mark 11, and the via hole pad.
An uneven layer (roughened surface) of a 2.5 μm thick P-Cu alloy is formed.

Then, the substrate 10 is washed with water, and the substrate 10 is placed in an electroless tin plating bath made of a tin borofluoride-thiourea solution.
It is immersed at 0 ° C. for 1 hour to form a tin-substituted plating layer having a thickness of 0.3 μm on the roughened surface of the Ni—Cu—P alloy.

As shown in step (C), the above adhesive is applied to the substrate 10 using a roll coater, left in a horizontal state for 20 minutes, and then dried at 60 ° C. for 30 minutes to obtain a thick film. An adhesive layer 16 having a thickness of 50 μm is formed, and then heated in a heating furnace at 170 ° C. for 5 hours to cure the adhesive layer 16. The adhesive layer 16 has translucency. This is to make it easy for the CCD camera 82 to recognize the target mark 11 covered with the adhesive layer 16.

Thereafter, the substrate 10 is placed on the XY table 80 shown in FIG. 1, and the target mark 11 formed on the substrate 10 is measured by the CCD camera 82 as described above. After measuring and correcting the deviation, the laser oscillator 60 irradiates a pulse light of 50 μsec with an output of 400 W. This light forms a hole 20 for a via hole in the adhesive layer 16 of the substrate (see step (D)).

In this embodiment, the target mark 11
Since copper is used, the reflectance is high and the CCD camera 82 can easily read. In addition, since copper does not transmit light, a positioning mark can be recognized by a silhouette, and C
Easy to read with CD camera 82. In this embodiment, copper is used as the target mark 11,
Instead of copper, various conductive metals that have high reflectivity and do not transmit light can be used.

Further, since the target mark 11 is formed simultaneously with the conductor circuit (the inner copper patterns 14a and 14b), there is no need to provide a separate step of forming the target mark.

In this embodiment, the substrate (500 mm × 500
mm), random 5000 holes are drilled. Here, as described above, the scan area of each galvanomirror is 30 × 30 mm, and the positioning speed is 400 points / second in the scan area. On the other hand, the number of step areas in the XY table 80 is 289 (17 × 17). That is, the laser processing is completed by performing the movement of 30 mm in the X direction 17 times and the movement in the Y direction 17 times. This X
-The moving speed of the Y table 80 is 15000 mm / min. On the other hand, the recognition time of the four target marks 11 by the CCD camera 82 is 9 seconds including the moving time of the table 80.

When the substrate 10 was processed by such a manufacturing apparatus, the processing time was 269.5 seconds.

The substrate 10 in which the holes 20 are formed is immersed in chromic acid for one minute to dissolve the epoxy resin particles in the resin interlayer insulating layer, and as shown in a step (E), to form the resin interlayer insulating layer 16. The surface is roughened, and then immersed in a neutralizing solution (manufactured by Shipley) and then washed with water. By applying a palladium catalyst (manufactured by Atotech) to the substrate 10 having been subjected to the surface roughening treatment, the adhesive layer 16 and the holes 20 for via holes are provided.
Attach catalyst nuclei to

Here, a liquid resist is prepared. DMD
An oligomer (molecular weight 4000) of a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd .: trade name: EOCN-103S) obtained by dissolving 25% of an epoxy group in acrylate, and an imidazole curing agent (manufactured by Shikoku Chemicals Co., Ltd.) 2 PMHZ-PW), an acrylic isocyanate (trade name: Aronix M215, manufactured by Toagosei Co., Ltd.) as a photosensitive monomer, benzophenone (manufactured by Kanto Chemical) as a photoinitiator, and Michler's ketone (manufactured by Kanto Chemical) as a photosensitizer. The following composition is mixed using NMP, the viscosity is adjusted to 3000 cps with a homodisper stirrer, and then kneaded with three rolls to obtain a liquid resist. Resin composition; photosensitive epoxy / M215 / BP / MK /
Imidazole = 100/10/5 / 0.5 / 5

As shown in step (F) in FIG. 5, the liquid resist is applied to both surfaces of the substrate 10 having been subjected to the above-described catalyst nucleus treatment using a roll coater.
Then, a 30 μm-thick resist layer 24 is formed.

Then, after the non-removed portion of the resist layer 24 is exposed by photoetching or laser irradiation with a small output, the resist layer is dissolved and developed with DMTG as shown in step (G), and a conductive circuit is formed on the substrate 10. forming a pattern portion 26a and the plating resist 26 with omission of the pattern portion 26b to form a target mark, further, exposed with 1000 mJ / cm ² at ultra-high pressure mercury lamp, for 1 hour at 100 ° C,
Thereafter, a heat treatment is performed at 150 ° C. for 3 hours to form a permanent resist 26 on the interlayer insulating layer (adhesive layer) 16.

Then, as shown in the step (H), the substrate 10 on which the permanent resist 26 is formed is subjected to a pre-plating treatment (specifically, a sulfuric acid treatment or the like and activation of a catalyst nucleus).
Thereafter, by electroless plating using an electroless copper plating bath, an electroless copper plating 28 having a thickness of about 15 μm is deposited on the non-resist forming portion to form an outer layer copper pattern 30, a via hole 32, and a target mark 111. A conductor layer is formed by an additive method.

By repeating the above-described steps, a further conductive layer is formed by the additive method. At this time, using the target mark 111 formed on the interlayer insulating layer (adhesive layer) 16, the CCD camera 8
The error is measured in 2 and a hole for a via hole is formed by a laser. By building up the wiring layers in this way, a six-layer multilayer printed wiring board is formed.

Although the galvano head is used as the scanning head in the above-described embodiment, a polygon mirror may be used. Although a CO ₂ laser is used as a laser oscillator, various lasers can be used.

[0038]

As described above, according to the present invention, hundreds to thousands of holes can be opened by irradiating a laser beam while securing the positional accuracy of a via hole. Mass production becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for manufacturing a multilayer printed wiring board according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a control mechanism of the manufacturing apparatus shown in FIG.

FIG. 3 is a process chart of processing by a control mechanism shown in FIG. 2;

FIG. 4 is a process chart for manufacturing the multilayer printed wiring board according to the first embodiment.

FIG. 5 is a process chart for manufacturing the multilayer printed wiring board according to the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 11 Target mark 50 Computer 52 Storage part 54 Input part 60 Laser oscillator 62 Mask 70 Galvano head 80 XY table 82 CCD camera

Claims (4)

(57) [Claims] 1. A laser light source for processing, a scanning head for deflecting the direction of laser light in X-Y directions, and a multi-layer printed wiring board used for processing a multilayer printed wiring board having an interlayer resin insulating material. Camera for reading positioning marks, XY table for mounting multilayer printed wiring board, input unit for inputting processing data of multilayer printed wiring board, storage unit for storing processing data or calculation results, and calculation The processing data is inputted from the input unit, and the processed data is stored in the storage unit. The position of the positioning mark of the multilayer printed wiring board placed on the XY table is measured by the camera. The processing data inputted is corrected based on the measured position of the positioning mark, and the scanning head, X-
The drive data of the Y table is created and stored in the storage unit. The control unit reads the drive data from the storage unit,
An apparatus for manufacturing a multilayer printed wiring board in which a laser beam is applied to a multilayer printed wiring board by controlling an XY table and a scanning head to remove an interlayer resin layer and form a hole. 2. The apparatus according to claim 1, wherein the positioning mark is made of a conductive metal. 3. The apparatus for manufacturing a multilayer printed wiring board according to claim 1, wherein said positioning mark is formed simultaneously with a conductor circuit. 4. A laser beam for processing, a scanning head for deflecting the direction of laser light in the X-Y direction, a positioning mark for the multilayer printed wiring board, and a positioning mark and an interlayer insulating layer formed on the multilayer printed wiring board. A XY table for mounting a multilayer printed wiring board, an input unit for inputting processing data of the multilayer printed wiring board, a storage unit for storing processing data or a calculation result, and an arithmetic unit. The multi-layer printed wiring board manufacturing apparatus is mounted on the multi-layer printed wiring board having the positioning mark formed on the XY table, and the processing data is input to the multi-layer printed wiring board. The processing section corrects the input processing data based on the measured position of the positioning mark, , Which was stored in the storage unit to create a driving data of an X-Y table, and the reads the driving data from the storage unit in the control unit,
A method of manufacturing a multilayer printed wiring board in which a laser beam is irradiated on the multilayer printed wiring board by controlling an XY table and a scanning head to remove an interlayer resin layer and form a hole.